What would bring him to me: wheezing, clicking or whistling, an open mouth when he is neither basking nor hot, bubbles or mucus at the nose or mouth, holding the head up or stretching the neck to breathe, a runny nose, going lethargic, going off his food.
You have explicitly ruled out most of that, which is why the thread is relaxed. If a brumating tegu shows any of it, that still needs seeing rather than being filed as part of the slowdown.